Emerging Treatments for Reactive Cutaneous Capillary Endothelial Proliferation.

Background: Reactive cutaneous capillary endothelial proliferation (RCCEP) is a common, burdensome adverse event that occurs in up to 88% of patients treated with camrelizumab. Without treatment, RCCEP is associated with social stigma and low quality of life. However, the optimal management of RCCEP remains inconclusive. Aims and Objectives: to elucidate the pathogenesis and clinical manifestations of RCCEP and systematically review the existing different therapeutic options for this dermatologic toxicity to encourage the selection of the most appropriate approaches for individual comprehensive management. Materials and Methods: As far as we know, we have systematically reviewed all cases complicated with RCCEP worldwide, and summarized the advantages and disadvantages of existing treatment methods. In addition, we report a successful case of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in a 61-year-old male Chinese patient who developed RCCEP after camrelizumab immunotherapy. Owing to the patient's advanced age, complicated medication history, and hyperalgesia, ALA-PDT was performed. The multiple lesions on his chest and buttocks showed rapid relief within 1 week of a single treatment session. Clinical recurrence was not observed within 6 months following treatment. Results: The current treatment of RCCEP is challenging and there is a lack of globally recommendations based on strict therapeutic regimens or clinical trials. Based on this case, we found that ALA-PDT is a safe and effective treatment option for RCCEP. This case also highlights the coexistence of several camrelizumab-induced dermatologic immune-related adverse events, which has never been reported before. Conclusion: New therapies for RCCEP have emerged in recent years. Dermatologists should raise better awareness of the complexity of drug eruption and the need for early diagnosis and medical intervention.